2 * iterator/iter_resptype.h - response type information and classification.
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39 * This file defines the response type. DNS Responses can be classified as
40 * one of the response types.
43 #ifndef ITERATOR_ITER_RESPTYPE_H
44 #define ITERATOR_ITER_RESPTYPE_H
50 * The response type is used to interpret the response.
54 * 'untyped' means that the type of this response hasn't been
57 RESPONSE_TYPE_UNTYPED = 0,
60 * 'answer' means that the response terminates the resolution
65 /** 'delegation' means that the response is a delegation. */
66 RESPONSE_TYPE_REFERRAL,
69 * 'cname' means that the response is a cname without the final
70 * answer, and thus must be restarted.
75 * 'throwaway' means that this particular response should be
76 * discarded and the next nameserver should be contacted
78 RESPONSE_TYPE_THROWAWAY,
81 * 'lame' means that this particular response indicates that
82 * the nameserver knew nothing about the question.
87 * Recursion lame means that the nameserver is some sort of
88 * open recursor, and not authoritative for the question.
89 * It may know something, but not authoritatively.
91 RESPONSE_TYPE_REC_LAME
95 * Classifies a response message from cache based on the current request.
96 * Note that this routine assumes that THROWAWAY or LAME responses will not
97 * occur. Also, it will not detect REFERRAL type messages, since those are
98 * (currently) automatically classified based on how they came from the
99 * cache (findDelegation() instead of lookup()).
101 * @param msg: the message from the cache.
102 * @param request: the request that generated the response.
103 * @return the response type (CNAME or ANSWER).
105 enum response_type response_type_from_cache(struct dns_msg* msg,
106 struct query_info* request);
109 * Classifies a response message (from the wire) based on the current
112 * NOTE: currently this routine uses the AA bit in the response to help
113 * distinguish between some non-standard referrals and answers. It also
114 * relies somewhat on the originating zone to be accurate (for lameness
115 * detection, mostly).
117 * @param rdset: if RD bit was sent in query sent by unbound.
118 * @param msg: the message from the cache.
119 * @param request: the request that generated the response.
120 * @param dp: The delegation point that was being queried
121 * when the response was returned.
122 * @return the response type (CNAME or ANSWER).
124 enum response_type response_type_from_server(int rdset,
125 struct dns_msg* msg, struct query_info* request, struct delegpt* dp);
127 #endif /* ITERATOR_ITER_RESPTYPE_H */